Added user-interface-base as a dependency, removed files that are now duplicate

Author: KierPalin

accessibility.ts

@@ -7,16 +7,15 @@
         "radio": "*",
         "microphone": "*",
         "datalogger": "*",
+        "user-interface-base": "github:microbit-apps/user-interface-base#v0.0.11",
         "display-shield": "github:microbit-apps/display-shield#v1.0.2"
     },
     "files": [
         "main.blocks",
         "main.ts",
         "app.ts",
-        "keymap.ts",
         "analytics.ts",
         "config.ts",
-        "accessibility.ts",
         "button.ts",
         "component.ts",
         "scene.ts",